1.    The commissioning of a new environment and there needs to be a pre go live validation of the environment that its going to fly under load, a load test will help validate the environment, find any pain points and help assess if there needs to be remedial action taken or of things will be a guaranteed success.

2.    Re-verify an environment  when there are plans to make a significant change which falls outside the original design parameters, this could be due to plans to significantly increase the number of users, change a way a process works with in the software or introduce additional load by adding a new application or entire product in to the environment.

3.    Trouble shooting of an existing environment where problems only occur under certain load conditions not easily reproduced out of the peak reporting periods. The load test is a repetitive process and can help identify trends, peaks/dips in performance and where there drops are coming from on an infrastructure level but also can help identify processes within the software itself which clash or are problematic.
 
Load testing may appear unnecessary, but if guarantee needs to be given or there is a risk of the project failing and the fallout involved with it, its more often then not much easier to assess an environment before it goes live and do remedial work as needed then try and fix a sizing/configuration related issue on a live system.
 
Load testing an EPM environment is a complicated activity, an expert is needed who knows the clients business processes and knows their application, normally a key user/administrator, Load Testing knowledge is needed, EPM knowledge is needed to the point where the scripted activities must be verified as actually happening, numbers changed, journals posted, pov set and reports run etc (the most common reason for failed load testing), if issues are identified then there needs to be technical knowledge about the Oracle EPM stack and the underlying infrastructure, can it be tuned? Is more hardware needed? Is it an Oracle related bug? IIIs it database related or VMWare? can we patch and retest ASAP…